The Arume, a dominating alien race of female humanoids (alien lesbians) has conquered Earth. With total control over the world they have begun live experiments on humans.One day, out of the blue, a girl that Shouta Yanami has never seen before in his life arrived at his house asking to have sex with him. How will this end for Shouta Yanami?

It's a story about alien invaders that's pretty sad. There are the three mangas listed here and also an anime (which is pure yuri). The mangas depict how the aliens abuse humanity to their hearts' content, while the anime is set 10 years before the invasion, featuring the romance between the captain of an alien ship that crashed into the earth and a high school girl with a particular tie to those aliens.